Cristina Zenato Instagram – Day 4, Question 4.
A Shark’s Eye
Before we go down the route of sharks’ vision, let’s remember that with over 520 species living between the surface and the abyss, the corals and the ice, this is generalized information.
The first and most fascinating fact about sharks’ eyes is that, unlike other fish, they can expand and contract their lenses to adapt to the presence or lack of light.
They also present an iris and cornea like we do.
But is it true that sharks have bad vision? It isn’t. Sharks have excellent sight; however, even the best of sight doesn’t allow them to see through misty, foggy, or siltout environments, and as such, we confuse bad vision with bad visibility when speaking about their capability to see.
Sharks also possess a secret weapon called Tapetum Lucidum (shining carpet), a coating in the back of the eye capable of reflecting and expanding light, providing night vision.
But what about colors? This question is still being investigated and answered. In general, all species of sharks possess what are known as rode cells, which are capable of detecting movement in low light as well as dark and light shadows.
Recently, some scientists discovered that sharks who live in a colorful environment, i.e., the Caribbean Reef sharks I work with daily, also present some cone cells designed to detect certain levels of colors.
In other words, each function is related to the world the shark species inhabit, and as always, we cannot have a one-size-fits-all answer.
Image of Crook’s eye, Caribbean Reef shark by @kewinlorenzen with @isotta_underwater_housings @waterproofinternational @fourthelementdive @diveshearwater @scubapro @peopleofthewater | Posted on 14/May/2024 16:49:31
